1. Field of the Invention
The invention relates to a reworking method for integrated circuit devices, and more particularly, to a reworking method for removing defects on layers of metal interconnections of the integrated circuit devices.
2. Description of the Prior Art
The fabrication procedure of integrated circuit (IC) devices is very complicated. Generally, it requires hundreds of different processes to complete the integrated circuit devices. Whenever the quality requirements of those processes are not being met, a reworking method is thereby needed.
Please refer to FIG. 1, which is a cross-sectional drawing of a conventional metal interconnection. In recent years, integrated circuit devices are formed as a plurality of multi-layered metal interconnections in accordance with a tendency toward higher density and higher integration, and to thereby increase the electrical connections between the metal interconnections themselves or between the integrated circuit devices and the metal interconnections. In a conventional method for fabricating a metal interconnection, a substrate 100 is provided with a base layer 101 and a dielectric layer 102 sequentially formed thereon, and procedures such as the photolithography process and the etching process are performed to form a plurality of vias/trenches for defining the metal interconnection patterns. Then, a barrier layer 104 and a metal layer 106 are sequentially formed in the vias/trenches, and a desired metal interconnection is obtained. As shown in FIG. 1, a base layer 110, a dielectric layer 112, a cap layer 114, and a hard mask layer (not shown) are sequentially deposited on the substrate 100, followed by the performing of procedures such as the photolithograph process and the etching process to form a metal interconnection pattern 116 for preparing another metal interconnection.
Please refer to FIG. 1 again. However, whenever some events such as particle contamination occurring in the above described deposition process, the existence of masking effect resulting from the existence of particles which leads to the forming of incomplete metal interconnection pattern 116 during etching, or having scratches formed on the wafer surface due to any external factor, the wafer thereby cannot be transferred to the next processing step. Thus, a reworking method is needed. Otherwise, the yield of the integrated circuit devices is to by significantly reduced. Sometimes the wafer even has to be discarded as scrape due to serious defects.